産業機械用の3次元免震装置の基礎的研究

（基本仕様と上下方向の免震性能の検討）

抄録

Recently, huge earthquakes were generated frequently, and seismic countermeasures are important problems. Seismic isolation technology which reduce the seismic load of the structure has been initiatively researched and developed. Consequently, the horizontal seismic isolation systems have been applied in various structures, for example, important industry facilities and general building. The 3-dimensional isolation systems which reduce the seismic load in not only the horizontal direction but also the vertical direction have been investigated too, however, the 3-dimensional isolation systems are little applied yet. The reduction of the vertical stiffness is necessary for high performance of the seismic isolation system in the vertical direction. The rocking vibration occurs by reduction of the vertical stiffness. The additional devices are necessary for suppression of rocking vibration. Consequently, the structure of the 3-dimensional isolation systems is complicated. However, the rocking vibration hardly occur by determining the vertical stiffness of device appropriately. In this report, the specification of the seismic isolation system in the vertical direction was investigated. Furthermore, the 3-dimensional isolation system with disc spring elements was investigated. The seismic response analysis was carried out by one mass model with disc spring elements. The response properties and effectiveness were evaluated. As a result, the response acceleration was reduced in the equipment whose natural frequency is approximately 10 Hz. Therefore, a fundamental performance was confirmed.